Development of an organic EL display as a candidate of next generation display techniques has progressed. Electro-luminescence is shortened to “EL” hereafter. The organic EL display is a self light emitting element and has a simpler structure than a liquid crystal display including a white backlight, a liquid crystal substrate (TFT substrate), and a color filter substrate. For this reason, production of a thin and light flexible display at low cost in future is expected.
An organic EL display device has advantages such as self-luminosity, high display quality, excellent response performance, and possibility of decrease in thickness and weight. Therefore, the organic EL display is often used as a mobile display (e.g., PTL 1).